High lift ratio hydraulic jack



J. w, PARKER 3,030,889

HIGH LIFT RATIO HYDRAULIC JACK 4 Sheets-Sheet 1 April 24, 1962 FiledSept; 28, 1960 1 2 o I IB/ I f 15 ATTORNEYS April 1962 J. w. PARKER3,030,889

HIGH LIFT RATIO HYDRAULIC JACK Filed Sept. 28, 1960 4 Sheets-Sheet 2INVENTOR. JAMES W. PARKER ATTORNEY April 24, 1962 J. w. PARKER 3,030,889

HIGH LIFT RATIO HYDRAULIC JACK Filed Sept. 28, 1960 4 Sheets-Sheet 3 2e21 &% a INVENTOR.

. JAMES w. PARKER W ATTORNEYS April 24, 1962 J. PARKER 3,030,889

HIGH LIFT RATIO HYDRAULIC JACK Filed Sept. 28, 1960 4 Sheets-Sheet 4JAMES W. PARKER w o. W

ATTORNEYS States,

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3,030,889 HIGH LIFT RATIO HYDRAULIC JACK James W. Parker, Dayton, Ohio,assignor to the United States of America as represented by the Secretaryof the Air Force Filed Sept. 28, 1960, Ser. No. 59,123 2 Claims. (Cl.103-11) (Granted under Title 35, U.S. Code (1952), see. 266) Theinvention described herein may be manufactured and used by or for theUnited States Government for governmental purposes without payment to meof any royalty thereon.

This invention relates to jacks and elevating supports such as hydraulicor fluid operated jacks, and more particularly to multiple telescopicleg hydraulic jacks, and has for an object hydraulic means forindependently and/ or selectively adjusting the lengths of the multipletelescopic legs of the jack for determining the elevation and locationof the upper jack supporting member.

A further object is the provision of tripod type jack which isapplicable and useful in raising crash-landed repairable aircraft, butmay be used in other applications where high lift and stability aredesired.

A further object is the provision of a high lift tripod type of jackwhich is capable of withstanding lateral loads without tilting orupsetting.

A further object is the provision of a tripod type high lift laterallyadjustable hydraulic jack which is simple in construction, relativelylight in weight, and portable, so that it can be towed behind a vehicle,and can also be successfully and firmly mounted on sloping surfaces.

A still further object is the provision of a tripod jack havingindependently hydraulically extensible multisectional telescopic legsand individual pumps and fluid supply means for selectively forcing ahydraulic liquid into each of said legs to extend the same.

A further object is a tripod type jack having the provision of commonpump actuating means for simultaneously or individually operating thefluid pump means whereby all of the telescopic legs can be extendedsimultaneously or any one or more of the legs can be extended orretracted independently of the remaining legs to adjust the supportingportion of the apex of the tripod jack in any direction relative to thebase of the jack structure.

Other objects and advantages of the invention will be apparent from thefollowing description and accompanying drawings in which like referencecharacters refer to like parts in the several figures.

In the drawings:

FIG. 1 is a perspective view of the improved hydraulic jack,illustrating the same in its fully elevated position;

FIG. 2 is a schematic View showing an application of the inventionrelating to a disabled aircraft, full lines showing the jack retractedand in position under the wing for a lifting operation thereof anddotted lines showing the jack extended to provide the lifting function;

FIG. 3 is an enlarged somewhat diagrammatic view, showing the jack fullyraised in full lines, partly lowered in dotted lines and fully loweredin dot and dash lines, only one leg of the tripod being shown in fulllines and the other two legs positions being shown in phantom,

and the power operating system being omitted;

FIG. 4 is a detailed perspective view of the improved pump or power unitand handle combination;

FIG. 5 is a fragmentary detailed view of one of the ball jointconnections at the lower end of one of the extensible tripod legs, andthe associated foot pad and traction wheels, parts being broken away andshown in section; and

FIG. 6 is a schematic view of the hydraulic system employed for theindividual and simultaneous hydraulic control of the tripod legs.

In the drawings, particularly FIG. 1, the invention comprises a lowerhorizontal base or channel frame 1 of triangular configuration. Mountedon the top of the plate 1, at each corner, as seen in FIG. 5, is a ballsocket 2 in which the lower ends of the telescopic tripod legs 3, 4 and5 are swivelly stepped, retainer cups 6 being provided and secured bybolts or screws 7 to the triangular channel frame 1.

Located below the ball end 8' of each of the legs 3, 4 and 5 is aspherically depressed casting or support 9 in the depression of which isa swivelly disposed foot pad 10 having a flat (or corrugated) lowersupporting surface 11. Located adjacent the lower ends of the legs 3, 4and 5 and suitably journalled on the channel frame 1 are the tractionwheels 12, 13 and 14, preferably carrying pneumatic tires 15. As shown,the wheels 15 are disposed parallel to each other and perpendicular to avertical plane extending through the lower ball heads 8 on the lowerends of the legs 4 and 5. The front wheel 12, adjacent the tripod leg 3may be mounted for swivelling action for steering the device when towedby a towing bar 16 which is pivoted on the cars 17' projecting from thefront end of the triangular frame 1.

At the rear portion of the frame 1, between the legs 4 and 5, is locateda horizontal supporting portion on which the hydraulic power supply andpump control means 18 is mounted.

As best seen in FIGS. 1 and 3, each of the telescopic legs 3, 4 and 5comprises a lower larger diameter cylinder 19 carrying the ball 8swivelled at its lower end in the sockets 2 and 6, a smallerintermediate sleeve piston 20, telescopically disposed in the cylinder19, and a still smaller diameter upper sleeve piston 21 telescopicallydisposed in the sleeve piston 20. The upper ends of the sleeves 21 areclosed and are pivoted at 22 to an upper load sustaining platform orplate 23 having a central or apex load supporting boss 24.

The upper plate 23 has a centrally disposed downwardly extending guiderod or sleeve 25 fixed thereto having an enlarged foot 26 at its lowerend which may be arranged to seat and rest on the central portion 27 ofthe base frame 1 when the jack device is fully lowered.

Slidably mounted on the guide rod 25 is a sleeve member 28 which ispivotally connected at its lower end at 29, by link members 30, to theupper ends of the intermediate sleeves 20, at 31.

When fully and partly extended the link members 30 constituteintermediate brace means between the extensible legs of the tripod, aswell as stabilizing means for maintaining the upper load sustainingplate in fully stabilized relation to the legs, both in the upright andtilted positions of the tripod structure.

Pressure fluid is admitted at 32 (FIG. 3), at the lower ends of thelower or larger leg cylinders 19 for extending the leg members as seenin this figure of the drawings to raise the jack to the full lineposition, and allowed to escape therefrom to lower the jack to itslower, dot and dash position.

Reference being made to FIGS. 1 and 4 and the schemat1c view in FIG. 6,the hydraulic power control means 18 is illustrated and comprises ahydraulic liquid reservoir or drum 33 which is connected by piping 34 tothe individual pumps 35, 36 and 37 for the legs cylinders.

Referring most particularly to FIG. 6 fluid from reservoir 33 issupplied to both ends of the pump cylinders through the check valves 38and delivered from both ends of the pump cylinders through check valves39 and piping 40 and 41, and connected delivery line 42, to the lowerends of the cylinders 19 through fluid restrictors 43.

A fluid return line 44 to the reservoir 33 is connected to each of thedelivery pipes 42 by a conduit 45 and has a control or shut-off valve 46therein. Also, a pressure gage 47 is connected to each of the conduits42 to indicate pressure in the cylinders 19, which can be calibrated toindlcate lifting stresses. Also, pressure responsive relief valves 48are connected in piping 49 between the conduits 41 and 44, openingtoward the conduit 44, and similar pressure relief valves 50 aredisposed in conduits 51 which are connected between the conduits 40 andthe return conduit 44, opening toward the conduit 44.

Referring to FIG. 4, the pump unit comprises the support or base 52 onwhich the pump cylinders 36, 35 and 37 are mounted in fixed parallelfashon and the piston actuator or pump 'rods 53 are pivotally connectedat 54 to the pump levers 55 intermediate their ends, link members 56pivotally connecting the ends of the pump levers 55 to the support orbase 52.

I The pump levers 55 extend forwardly in parallel relat1on to each otherand are of equal diameter. An actuatlng handle member 57 is providedwhich comprises three parallel sleeve members 58, 59 and 60 of equalsize adapted to be selectively telescoped over any one or more of thepump levers 55 for actuation thereof. These pump actuator sleeve membersare rigidly fixed on a cross bar or plate 61 having an actuating handlemember 62 pro jecting from the opposite side of the plate 61, as shownin FIG. 4.

As will be observed, the handle device can be inserted to dispose one ofthe sleeve members 59, for instance the center sleeve member on any oneof the pump levers 55 for individual selectvie pumping actuationthereof, also any two of the sleeve members, for instance the center andone of the outside sleeves may be inserted on any two adjacent pumplevers for simultaneous pumping of any two adjacent pumps for extendingany two of the legs of the jack simultaneously, and also all three ofthe sleeve members 58, 59 and 60 can be telescoped over all three of thepump levers 55 and all three pumps actuated s multaneously to extend allthree of the legs of the jack simultaneously. Since the cross sectionalarea of the upper telescopic portions 21 are smaller than theintermediate portions 20 or the lower cylinders 19, the upper portionswill be extended last in the raising of the jack and will be retractedfirst in the lowering operation.

If desired the links 30 and the rod and sleeve member 28 may be omittedand the legs connected to the plate 23 In closer relation to the apex ofthe tripod without departing from the invention as defined in theclaims.

In the operation of the jack, assuming it is desired to extend all ofthe legs simultaneously and uniformally, the actuating handle member 62is disposed to telescope all three sleeve handles on all three of thepump handles 55. Up and down movement of the actuating handle memberpumps, hydraulic fluid from the reservoir 33 through the conduits 42 andcheck valves 38 and 39 and into the jack cylinders 19 as seen in FIG. 6,extending the legs to elevate the jack, the relief valves 46 preventingan overload pressure in the jack cylinders 19.

When it is desired t Wer the jack the individual shutoff valves 46 areopened to allow the fiuid in the cylinders 19 to return back to thereservoir, the return being somewhat retarded by the restriction 43preventing rapid collapse of the jack members 3, 4 and 5.

As seen in FIG. 2, a disabled aircraft is shown schematically at 63 withits wing 64 inclining downwardly and the wing tip in contact with theground. The jack device may be towed into position on its tractionwheels 12, 13 and 14, which may be inflated just sufficiently to supportthe foot pads 10 above the ground. By proper manipulation of the handlemember 62 relative to the pump handles 55, as previously explained, thejack legs may be adjusted to incline the jack to the right, as shown,normal to the span of the wing. As pressure is selectively applied tothe legs and the load of the aircraft is applied to the apex of the jackthe tires may flatten allowing the foot pads to contact the ground andfully support the jack in position. As the pump members are actuated andthe legs selectively extended to the dotted line position in FIG. 2, theapex supporting portion of the jack can be shifted laterally as it israised to keep the apex contact portion in engagement with the sameportion of the wing as this portion moves over to the left, rather thanpermitting the lifting contact point to slide across the wing,spacewise, and possibly doing damage to the wing surface.

Of course, if the jack is placed on a slanting or inclined surface, suchas a hill side, proper initial selective manipulation of the multiplehandle member on the pump handles can straighten up the jack so that thecenter of lift 11 is directly over the center of the inclined base platestructure 4, after which all of the pumps can be manipulatedsimultaneously to raise the apex portion vertically.

Suitable packing rings of conventional design are, of course, providedbetween the upper ends of the main cylinder 19, the sleeve 20, and theupper sleeve or plunger 20; also stop means of conventional design areprovided for limiting the extension of the sections 19, 20 and 21 of thetripod legs.

It should be evident that the precise details set forth above are forexemplary rather than for restrictive purposes, and therefore certainchanges and modification may be resorted to without departing from thespirit and scope of the invention as defined in the accompanying claims.

What I claim is:

1. A multiple and selective hydraulic pumping device comprising asupport, a plurality of pump cylinders mounted on said support inclosely equally spaced parallel relation in a common plane, a pumpactuating rod for each cylinder extending outwardly from said cylindersin equally spaced parallel relation to each other in said common plane,a plurality of identical pump actuating levers of equal lengthspivotally connected at one end to said support, one for each rod,pivotally connected intermediate their ends to said rods, said leversextending across said ends of said cylinders in equally spaced parallelplanes normal to the aforesaid common plane, said levers havingidentical handle engaging extremities at their free ends disposed in theaforesaid equally spaced parallel planes, a separate actuating handlemember for selectively and collectively actuating said pump actuatinglevers, comprising a main handle portion and a plurality of identicalpump actuating lever engaging portions fixed on said main handle portionin equally spaced parallel relation to each other, in a common plane, ata distance equal to the distance between the said identical handlereceiving extremities, for actuating engagement therewith, whereby anyof said identical handle engaging extremities can be disposed inactuating engagement with any of said handle engaging extremities tooperate said pump actuating levers individually or collectively.

2. A multiple and selective hydraulic pumping device comprising ahorizontal support, a plurality of pump cylinders mounted on saidsupport in close equally spaced parallel vertical relation in a commonvertical plane,

conduit means for supplying a hydraulic fluid to said pump cylinders,delivery conduit means from each of said cylinders for selectivelydischarging the hydraulic fluid from each of said pump cyilnders, a pumpactuating rod for each pump cylinder extending upwardly from saidcylinders in equally spaced parallel relation in the said common plane,a plurality of identical pump actuating levers of equal length pivotallyconnected at one end to said support, one for each rod, pivotallyconnected intermediate their ends to the upper ends of said rods, saidlevers extending across the upper ends of said cylinders and terminatingat their free ends in identical cylindrical handle engaging extremitiesdisposed in equally spaced parallel planes normal to the aforesaidcommon plane, a separate actuating handle member for selectively andcollectively actuating any one or more of said pump actuating leverscomprising, a main handle portion, and a plurality of identicalcylindrical handle engaging extremit'y sleeves fixed to said main handlepontion in a common plane, in parallel relation to each other, havingtheir axes spaced apart a distance equal to the distance between thelast mentioned equally spaced parallel planes, for telescopicallyreceiving any one or more of said identical cylindrical handle engagingextremities therein, whereby said handle is disposed to telescopicallyengage and actuate any one or more of said pump actuating levers.

References Cited in the file of this patent UNITED STATES PATENTS308,509 McLeod Nov. 25, 1884 337,402 Hines Mar. 9, 1886 2,091,876 OldhamAug. 31, 1937 2,337,831 McGovern Dec. 28, 1943 2,341,542 Grime Feb. 15,1944 2,407,796 Page Sept. 17, 1946 2,499,563 Bill Mar. 7, 1950 2,605,999Schultz Aug. 5, 1952 2,809,494 Matson et al Oct. 15, 1957 FOREIGNPATENTS 401,386 Great Britain Nov. 16, 1933 539,944

Great Britain Sept. 30, 1941

